https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100365
Bug ID: 100365
Summary: bogus -Wreturn-type with a return statement with an
erroneous expression
Product: gcc
Version: 11.1.0
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The C front end issues a spurious -Wreturn-type warning for return statements
with erroneous arguments in non-void functions. The C++ front end does a
better job (and Clang better still):
$ cat z.c && gcc -S -Wall z.cint f ()
{
return x;
}
int g ()
{
return (int);
}
int h ()
{
return ++0;
}
z.c: In function ‘f’:
z.c:3:10: error: ‘x’ undeclared (first use in this function)
3 | return x;
| ^
z.c:3:10: note: each undeclared identifier is reported only once for each
function it appears in
z.c: In function ‘g’:
z.c:8:15: error: expected expression before ‘;’ token
8 | return (int);
| ^
z.c: In function ‘h’:
z.c:13:10: error: lvalue required as increment operand
13 | return ++0;
| ^~
z.c: In function ‘f’:
z.c:4:1: warning: control reaches end of non-void function [-Wreturn-type]
4 | }
| ^
z.c: In function ‘g’:
z.c:9:1: warning: control reaches end of non-void function [-Wreturn-type]
9 | }
| ^
z.c: In function ‘h’:
z.c:14:1: warning: control reaches end of non-void function [-Wreturn-type]
14 | }
| ^
G++ issues just the four errors below:
z.c: In function ‘int f()’:
z.c:3:10: error: ‘x’ was not declared in this scope
3 | return x;
| ^
z.c: In function ‘int g()’:
z.c:8:11: error: expected primary-expression before ‘int’
8 | return (int);
| ^~~
z.c:8:11: error: expected ‘)’ before ‘int’
8 | return (int);
| ~^~~
| )
z.c: In function ‘int h()’:
z.c:13:12: error: lvalue required as increment operand
13 | return ++0;
| ^
Clang:
z.c:3:10: error: use of undeclared identifier 'x'
return x;
^
z.c:8:15: error: expected expression
return (int);
^
z.c:13:10: error: expression is not assignable
return ++0;
^ ~
3 errors generated.
